As the EV market continues to grow and the demand for at-home charging stations increases, electrical codes have been amended to require ground fault protection of NEMA 14-50 outlets at residential locations. The new codes have complicated the installation of charging stations since most charging stations already have internal ground fault circuit interrupter (GFCI) protection. Adding additional GFCI protection is resulting in nuisance tripping of these breakers for customers.
This overview dives into the issue and explores various ways for electrical contractors to overcome the challenge of connecting EV charging stations to the grid.
The National Electrical Manufacturers Association (NEMA) is the trade association for electrical equipment manufacturers in the United States. Electrical outlets and plugs in the U.S. are specified by NEMA, and most standard cooking ranges and electric dryers in your home use a NEMA 14-50 outlet for power.
Electric vehicle charging outlets can also use the NEMA 14-50 standard outlet, and these are becoming more prevalent as EVs gain popularity and customers now require and desire charging stations at their homes.
Electrical codes have recently been amended to deal with the influx of these applications around the country. New codes state that a GFCI breaker must be installed on a NEMA 14-50 outlet used for EV charging. A GFCI breaker is designed to prevent a shock hazard when an electrical circuit comes in contact with water. This is a safety precaution to help prevent injury and death.
GFCIs normally add a layer of protection for users. However, they can also lead to nuisance tripping when used in conjunction with a Level-2 charger that will shut down the associated circuit and halt charging on your vehicle. This will cause headaches for homeowners who will have to continually reset the tripped breakers.
NEMA plugs are also subject to wear and tear with the continual plugging and unplugging of the units. So, in addition to the nuisance breaker trips, the plug life cycle will also be a challenge.
Hardwiring your EV charger is a more permanent solution. It requires a dedicated circuit, which can be a more reliable method to charge your vehicle.
There are some questions to ask before you begin to add your charging station to your electrical panel:
A hardwired charger is a more stable and permanent solution. If you have enough capacity and space on your panel, this could be a good option. Other benefits include:
These are a few things to consider when installing a charging unit at your residence.
If your panel can’t handle the extra load of an EV charger, you have a few options. You can upgrade your panel to accommodate the new device — but with the installation fee, permitting and dealing with the power company, this can be costly.
Your other option is a DCC-12 management system for EVs. Install this device between the Level-2 charger and your panel. The DCC-12 bypasses the circuits in your panel and regulates via smart sensing technology. It can detect when there is a low enough load in your house, typically when the household is sleeping, and then start to charge the EV. If the load in the house picks up, it will see this increase and stop the charging process until the load in the house reduces again.
DCC-12 solves the standing issue since it allows all homeowners, even those who do not have an upgraded panel, to charge an EV at home.
The DCC-12 system is great for EV charging stations because it gives EV owners peace of mind. There’s no risk of overloading their panels and the EVs will always be charged when needed.